The fields of application for the pluggable ST-COMBI spring-cage terminal blocks has been added to with solutions for larger conductor cross sections and a higher nominal current. The product range includes both feed-through terminal blocks with one cable entry and four-wire terminal blocks with two cable entries. Ground terminal blocks with the same shape and the same pitch are available for the various base terminal blocks. Contact is made by simply snapping the terminal block onto the mounting rail. The corresponding plug types SP 4... can either be ordered ready assembled with 1-15 positions, or the individual components can be ordered for applicationspecific assembly. At every connection point of a conductor to the base terminal block or connector there is a testing facility for a 2.3 mm test plug.